Great! It is easy to know the difference between right and wrong concerning those things. Even unbelievers know it is wrong to do those things which is why there are national laws against some of them. There are also NT admonitions against such things which are really just reminders of OT laws. There are also NT admonitions to do the positive things you mentioned like caring for the Body and sharing the Gospel.
John 7:17 If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself.
I do not believe we need to wait until the Holy Spirit convicts us or impresses on us the need to keep the Sabbaths (weekly and annual) holy or eat clean. Yahweh has already told His people what they must do. He has revealed His will to us. Most don't do it, not because the Holy Spirit has not yet impressed it upon them, but because Christian leaders have impressed it upon them to NOT do those things. For Christians today, it is a matter of overcoming being taught falsely. That requires rightly dividing the word. We haven't discussed the Scriptures people use to teach the dietary laws are abolished. We are only discussing Colossians 2 concerning Feasts and weekly Sabbaths.
Are you aware that the "Law of Moses" and the "Law of Yahweh" are the same thing? Yahweh revealed His law through Moses which is why it is called the Law of Moses.
Behold, I have taught you statutes and judgments, even as Yahweh my God commanded me, that you should do so in the land where you go to possess it.
Keep therefore and do them; for this is your wisdom and your understanding in the sight of the nations, which shall hear all these statutes, and say, Surely this great nation is a wise and understanding people.
For what nation is there so great, who has God so nigh unto them, as Yahweh our God is in all things that we call upon Him for?
And what nation is there so great, that has statutes and judgments so righteous as all this law, which I set before you this day? Deuteronomy 4:5-8